George Takei as a child was incarcerated with his family in the U.S. camps among more than 120,000 Japanese Americans who were taken from their homes in West Coast states and detained in camps because of their ancestry. His family was held in the Santa Anita, Rohwer and Tule Lake camps. He has been active in camp memorial/preservation efforts.
For more on the history of the incarceration generally, the Densho Encyclopedia is a good resource: https://encyclopedia.densho.org/contents/